It is known that the motion of the waves produced by the wind in the sea or lakes represents a source of energy which consists in the use of the kinetic energy contained in the wave motion, from which it takes its name. It is classified amongst the so-called “alternative energies” and “renewable energies”.
The use of the energy of wave motion has been recently trialled in various European research projects in the energy field and in particular if the wave motion is used for the production of electricity the system is called chemoelectrical.
There are various techniques for using the wave motion and the conversion of the energy of the waves into electricity is the subject of various studies and embodiments, based on various physical principles.
There are prior art technical solutions wherein energy is obtained from the wave motion of the sea using devices, generally floats, which perform a guided movement according to a vertical alignment with each passage of the wave.
For example, according to some solutions, through the passage of the waves in a channel with a progressively decreasing width or by means of special ramps, the waves reach greater heights and it is therefore possible to fill a basin to a higher level than that of the level of the water basin. The continuous flow of the water collected, using suitable civil works, and the passage through turbines hydraulic, allows the generation of a certain quantity of electricity.
According to further solutions, the movement of the waves can actuate hydraulic motors to be coupled to an electricity generator through the use of a semi-submerged floating structure, comprising various long elements connected in series with special joints, which is moved by the waves varying the relative inclination of the various elements. Specific hydraulic pistons located at the joints put a fluid in motion, under pressure in an internal circuit, which drives the hydraulic motor, installed inside one of the elements.
There are also prior art plants for using waves comprising a submerged structure anchored to the sea bed, equipped with an air chamber, which is subject to decompression-compression cycles due to the variation, created by the waves, of the column of water above, and other systems consisting of a float, anchored to the sea bed by a system which is able to transfer the mechanical energy of the relative motion between the sea bed and the float, by means of suitable mechanisms, to a generator.
The use of these prior art systems for the use of wave motion has highlighted certain problems, the main one of which is represented by efficiency or performance limitations due to the low frequency of the wave motion, when, on the contrary, high speeds are preferable for the operation of electricity generators.
More specifically, the current systems for using energy deriving from the recovery of the wave motion are subject to the sudden changes, often considerable, to the waves due in some cases to the variation of the tides or to the different weather conditions or in other cases to the different intensity of the passage of boats.
These variations of the flow of the wave motion determine an irregularity of the thrusts exerted on the traditional energy recovery means, creating difficulty in establishing a mean undulation useful for the conversion of the sussultatory motion into constant motion of the crank mechanism.
The above-mentioned problems have been encountered for example in the solutions of patent documents U.S. Pat. No. 4,698,969, JP H02 221682, GB 2239293 and US 163451, which involve the use of means for recovering energy from the wave motion associated with containment structures which are completely inadequate to limit the variations, which are often very high, in the intensity of the wave motion.